Luna E-6 No.2, also identified as No.1, and sometimes known in the West as Sputnik 25, was a Soviet spacecraft which launched in 1963, but was placed into a useless orbit due to a problem with the upper stage of the rocket that launched it. It was a 1,500-kilogram (3,300 lb) Luna Ye-6 spacecraft, the first of twelve to be launched. It was intended to be the first spacecraft to perform a soft landing on the Moon, a goal which would eventually be accomplished by the final Ye-6 spacecraft, Luna 9. There was a pause of almost three years between the last Luna E-3 attempts in 1960, both of which ended in failure, and the first E-6 launches.

Wikipedia: https://en.wikipedia.org/wiki/Sputnik_25. Original timeline Wikipedia link: https://en.wikipedia.org/wiki/Sputnik_program. Related NASA reference: https://nssdc.gsfc.nasa.gov/planetary/chronology.html#1963. Description adapted from Wikipedia contributors (CC BY-SA 4.0; https://creativecommons.org/licenses/by-sa/4.0/).